Bearing assembly for absorbing vibrations of centrifuge spindles and the like



*.J. E. coo BEARING ASSEMBLY EOE ABsoEEING vIBEA'rIoNs HG. Z f7 i 16a I4 Z Z 10b x I2C y Q l l5 .IP 12b- ]Z 13a lla A II INVENTOR. James. E'. Coo/e'.

BY v A TTo RNE ys atented May 26, 1953 i; BEARING ASSEMBLY FoR ABSORBING VIBRATIONS 0F CENTRIFUGE srINDLEs AND {FRET-LIKE *James-Edward fook, Poughkeepsie, A'1 \I.""Y.,- asn sLgnor'v lto -The llel Laval 'SeparatorCoinpam New York, N. Y.; a corporati'on'fNewlllersey f Application. January 2, 19m-,Seriana 204,043

15 Claims. -r1

tions.

The usualbea'ring asseiiiblies for 'this' 'purpose c'o'iiipri'sel a "yielding 'radial support* surrounding 4"the spindle'beang' yand acting" to cushionthe l'lateral''v'ifn'ations of the'spindle'iand b'earingj'so as' 00'T'dlleeith'ilbatons 'transmitted t vthe 'Stationary'frame or' 'housing 'ini Which the "parts ro- L tate. The yieidingrauaiSupport-nasgenerally taken the" forn'lbf aseries'of radial springs'or 'an annular rubber cushion disposedaround the bear- `ving. *Both of these"lorrnsas'usedheretofore have v'met'A With certain' difliculties For -`example, the l radialv springs s''fnrnetirne` fail 'to'center the spindle "p1operly-y ai ter 'the bearing i assembly' is" installed, "which brings @about an t'-undesirable i condition. "While-*the :usefrubber cushion largelyorene llilly avoids this fpaltcillardfllellty;-theilherellt i Characteristics "Offtlley rllbbel47 have lesilltedin other1difficulties?'dueiprincipallyftoi thestfresses to which the rubber is subjected iiihencompressed l r i? inthe-usual manner around vthe bearing.

Another-'1diicultywitlfvtheseprior b'ea'ringl asselnbl-ies is-thatthey require-considerable :space 'in @the eentriuge housing-*since the housing" rece-ss for the assembly must be of suiiicient diameter to accommodate-'the' compression springs y or cushion radiating ifromltheibearing itself. In centrifuges n ofi the' smaller: sizes,;particularly, i. the relatively r-largeoverall"diameter ofithefbearing assemblyfis a-"serious disadvantage.

The present invention iis fdirected I'tothe provif sionv ot-'sani impr'oved -fbearing'assembly `wherein the 'lateral' vibrations fof" the:4 spindle-arev cushionedbya rubber-like -body which :is arranged so las to iavoid a #heavy f concentration of 1 stresses therein and which, at Ithe-:same time', does vnot increase the diameter of the assembly substantially beyond' the diameterof the'v bearing itself.

A bearing assembly made according to the invention comprises stationaryr 'housing surrounding the spindle with a clearance. l Abearng in the housingelosely surrounds the `spindle and has innerfand outer races, there' being an annular Sspace between the outer race 'aand the sidel -Wall fotthe'housing. An annular/element closely` sur- #rounds and is movable radiallyf'withvthe-vouter race, this element being preferably in the form of a sleeve in which the outer race has an axially sliding fit. The sleeve is spaced from the side wall of the housing and has a part projecting axially of the spindle from the annular space between the housing and bearing into 'the clearance between the `spindle 'and housing, the' sleeve being spaced"fr'ointhe spindle. Anannular body'bf 'rubber-'like "rn'a'terial is"'displacedaxially 'from the "annularspace'be'tween Athe'bearing and housing and 'is secured to the' projecting part of the sleeve. The inner portion of this body is spaced 'from 'the 'spindle but is located nearer the spindle axis than lo" 'is the "inner: Wall'of'the annular spacev between like'body overlies' thebearing. A'r'etaining'inem- 'the 'bearing and the housing, so lthatthe rubberber on 'the' frame is 'spaced` from' the'sleeveA4 and surrounds and 'engages the "rubber-like" body.

sists radial V'movenflent i of the` sleeve, the bearing and the" spindle.

-With" this arrangement; therubber-like rbody y or'cushioning :the vibrations' canbemade with a large' radial"thickness-without vappr'eciably 'increasing theoverall"diameter'of the bearing as- -sembly, and th-ereforeVthe housing recessv for-the assembly may be of relatively'sinalldiameter. A13l the same-timejbyreasonI yof thenianner of 'connecting the rubber-like bodyto the-housing andI the Abearing; the Vinner lp'o'rtion'of lthis body `overlying the bearingffoanl `ben'iade tolundergoa shear-like action Link resi's'tingthe llateral"vibra- 'ltions of the spindle,j the stresses 'tendingl'toshear the body being distributed quite -uniformlyaround the'r'ubb'er-like fbo'dy.

For a better understandingA ofi-the invention,

' reference maybehad to thev accompanying'drawing, in which Fig. 1 isa vertical sectional view-ofapreferred "Fig, 1.

j'Referringto the drawing; the numeral i 0 Adesignates the :frame or lniu'singofl a'cen'trifuge having me'diate ball bearings I2C. IThe "inner race' lila `1S` Seated bn a shulder' l la' Of thespindle, So vthat the'lbeaiing 4moves verti'callymivith Y'the' spindle. "The" ib/earingl 2 is' located in a recess in the upper portion of the housing lli, this recess providinga clearance lila between the spindle and the side Wall of the housing. Between the outer race |2b of the bearing and Athe side wall of the housing is an annular space |019 which permits radial movements of the bearing relative to the housing incident to rotation of the spindle.

An annular element in the form of a sleeve I3 closely surrounds the outer race I2b, the bearing having a sliding t in the sleeve to permit axial movement of the bearing relative to the sleeve. The sleeve I3 projects upwardly from the annular space IUb into the clearance Ia, the sleeve being spaced from the side wall of the housing. At its upper or projecting portion the sleeve I3 is secured to an annular rubber-like body I4, as by molding the sleeve to the body I4. The rubber-like body is located in the clearance I0a between the spindle and the housing and is spaced axially from the annular space I0b and the bearing I2. It has an inner portion I4a fitted closely in the upper portion of the sleeve, this inner portion being spaced from the spindle II but located nearer the spindle axis A than is the inner wall of the annular space I0b, that is, the outer surface of the race I2b. Thus, the

inner portion I4a of the rubber-like body overlies a substantial portion of the bearing I2 in axially spaced relation thereto. The body I4 also has an outer portion I4b extending over the top of sleeve I3 and outwardly a substantial distance therefrom.

A retaining member I5, which is shown in the form of an outer sleeve, is fitted closely in the housing recess Illa and has a flange Ia closely surrounding the outer portion I4b of the rubberlike body. This ilange I5a is seated on the top of the housing so as to support the sleeve I5 therein. A cover piece I6 is releasably secured to the outer sleeve I5, as by means of ya bayonet type joint. The cover I6 extends inwardly over the rubber-like body I4 and has a neck Ilia surrounding the spindle but spaced slightly therefrom, the spacing being adequate to accommodate the maximum radial displacements of the spindle incident to its rotation. Above the cover I6 is a dust cover I1 secured to the spindle and extending downwardly around the neck I6a in spaced relation thereto.

In the operation of the new bearing assembly, the inner sleeve I3 partakes of the radial movements of the spindle II and its bearing I2, although this sleeve permits axial movements of the spindle and bearing in the sleeve. The radial movements of the sleeve are resisted yieldingly by the rubber-like body I4. That is, While the latter is conned by the yretaining member I5 against bodily movement, the inner portion of the body I4 can iiex radially incident to the lateral movements of the inner sleeve I3. This ilexing is brought about by the tendency of the radial movements of sleeve I3 to shear the inner portion I4a of the body from the portion overlying the sleeve I3. In addition to this resistancein-shear imposed by the inner portion I4a, a further resistance to radial movements of the bearing is imposed by the outer portion I4b of the rubber-like body. That is, as the sleeve I3 is displaced in one direction from the normal axis of the spindle, the part of the outer portion I4b lying in the direction of displacement is compressed against the flange I5a of the retaining member. Due to the tendency for the rubberlike body I4 to assume the shape illustrated in Fig. 1, this body acts to return the spindle to its center position,

It will be apparent that the new assembly is of relatively simple construction and, while occupying only a small space in the housing I0, is extremely eiective to damp the radial vibrations of the spindle. Since the forces imposed upon the rubber-like body I4 incident to radial displacement of the spindle are distributed over a considerable portion of the rubber-like body, the latter can be used for a long period of time without replacement. The entire assembly, Including the parts I3, I4, I5 and I6, can be removed as a unit from the housing along with the spindle II, since the retaining member I5 is slidable in the housing recess Illa. The removable cover I5 permits ready access to the cushion I4.

1. A bearing assembly for the spindle of a centrifuge, or the like, which comprises a stationary housing having a side wall surrounding the spindle with a clearance, a bearing in the housing closely surrounding the spindle and having inner and outer races, there being an annular space between the outer race and the side wall of the housing, an annular element closely surrounding the outer race and movable radially therewith, said element being spaced from the side Wall o1' the housing and having a part projecting from said space axially of the spindle and into said clearance in spaced relation to the spindle, an annular body of rubber-like material displaced axially from said annular space and secured to said projecting part, the inner portion of said body being spaced from the spindle but located nearer the spindle axis than is the annular element, and a retaining member on the housing spaced from said element and surrounding and engaging said body to conne the same against bodily movement while said inner portion yieldingly resists radial movement of said element, bearing and spindle, the rubber-like body having said inner portion thereof fitted closely in the annular element and having another portion extending outwardly from said annular element to the retaining member.

2. A bearing assembly Iaccording to claim l, in which the retaining member has a flange engaging the outer periphery of the rubber-like body and also has a shoulder axially supporting said body.

3. A bearing assembly according to claim 1, in which the retaining member is a sleeve surrounding said element yand slidable axially in the side wall of the housing, the sleeve having an outwardly extending part resting on the housing.

4. A bearing according to claim 1, comprising also a cover overlying the rubber-like body and releasably secured to the retaining member.

5. A bearing assembly according to claim l, in which the outer race of the bearing has an axially sliding t in said element.

JAMES EDWARD COOK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,387,158 Leitch Aug. 9, 1921 1,695,230 Curtis Dec. 11, 1928 2,526,443 Woodson Oct. 17, 1950 

